ZeoMet

Zeolites serve as storage media in thermochemical heat storage systems, which are considered to have great potential for the seasonal storage of heat from solar thermal systems or for the more flexible use of industrial waste heat. Some of these crystalline aluminosilicates can store up to a quarter of their mass as water in nanoscale pores, releasing the enthalpy of sorption in the form of heat that can be used in heating circuits. If the water is expelled again at a higher temperature, the sorption capacity is restored, which corresponds to an energetic loading of the storage. However, the processes of energy exchange are hindered by the poor thermal conductivity of the material.

The project for vacuum metallization of zeolite granules for heat storage applications aims to increase the thermal conductivity of such granules by means of a surface layer and to improve heat transfer both between the pellets and between metallic heat transfer structures and the zeolite bed.

The basic scientific and technical approach is to vaporize the zeolite material, which is available as granules, in a vacuum coating plant for bulk material with a gas-permeable but at the same time good heat-conducting layer of aluminum, which does not hinder the transport of the working medium water vapor but considerably facilitates the heat transport in a bulk material.

The project is intended to make a significant contribution to overcoming the deficits of this technically and economically promising type of thermochemical storage.